Within the last few years, methicillin-resistant Staphylococcus aureus (MRSA) strains encoding Panton-Valentine leukocidin (PVL) have emerged and spread worldwide. This epidemic can be attributed to a small number of distinct clones. The present study used a novel assay, based on multiplex linear DNA amplification and subsequent microarray hybridisation, to simultaneously detect all relevant exotoxins, antimicrobial resistance determinants and the allelic variants of agr. The genes of the staphylococcal exotoxin-like (set) locus were also included for typing purposes. This assay, together with multilocus sequence typing (MLST) and spa typing, was applied to 56 clinical isolates and reference strains representing all major pandemic PVL-MRSA lineages, as well as to phylogenetically-related strains and putative ancestors. Array hybridisation results allowed the assignment of isolates to clonal groups, which were in accordance with MLST and spa typing data. Ten distinct clonal groups of PVL-MRSA (ST1, ST5, ST8, ST22, ST30, ST59/359, ST80/583, ST88, ST93 and ST152), including 12 MLST types, were identified and analysed with regard to resistance determinants and genes coding for exotoxins. The array hybridisation data confirmed that pandemic PVL-positive strains originate from very diverse genetic backgrounds, and provided insights into the evolution of some lineages. The DNA microarray technique provides a valuable epidemiological tool for the detailed characterisation of clinical isolates and comparison of strains at a global level.
Bibliographical noteFunding Information:
Part of this work was supported by a grant from the Technical University of Dresden. Reference strains were provided by the Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) and by the Institut Pasteur, Paris. We acknowledge helpful discussions with E. Jacobs and W. Rudolph. The authors thank all clinical colleagues who referred patients or submitted isolates. We are indebted to A. Ruppelt, M. Ganner, S. Kolewa, I. Engelmann, I. McCormick-Smith, E. MÜller, T. Pryce and J. Sachtschal for technical assistance. R. Ehricht and P. Slickers are employees of CLONDIAG chip technologies.
Copyright 2017 Elsevier B.V., All rights reserved.
- Community-associated MRSA
- DNA microarray
- Methicillin-resistant Staphylococcus aureus
- Panton-Valentine leukocidin